An expansion or anchor bolt (hereinafter referred to as “expansion bolt”) is a well-known type of fastener that is used for securing objects to a board-like, support structure (e.g. decking, sheathing, wallboard, or the like). One of the most common of this type of fastener is one which has an expandable anchor mounted on the lower end of an elongated, central threaded member (i.e. bolt, screw, etc.; hereinafter referred to as “screw”).
To secure this type of fastener in place, a hole is drilled through the support structure (e.g. board) and the lower end of the expansion bolt is passed through the hole until the lower expandable portion of the anchor lies in or is completely below the board. When the bolt is so positioned, a flange on the top of the anchor will engage the top surface of the board and the upper end of the screw will extend up through the hole and extend above the board. The upper end of the screw is then gripped and pulled outward from the upper surface of the board. This movement causes the anchor to expand below the board thereby anchoring the expansion bolt in place. An object can then be mounted onto the exposed portion of the screw of the now anchored, expansion bolt to secure the object on the board.
Various tools are used to set this type of expansion bolt. For example, in some instances, simple pliers or like tools have been used to grip and pull the upper end of the screw to set the bolt. As will be recognized, such gripping tools are inefficient, especially where a relatively large number of bolts need to be installed, and can cause serious damage to the threads on the screw.
Recently, specialized tools have been developed for quickly and efficiently setting this type of expansion bolt without causing damage to the bolt. More specifically, relatively small, hand-held “guns” are commercially available which loosely engage the head of the screw of an expansion bolt and then pull the screw outwardly to quickly set the bolt without damaging the screw. These guns are basically comprised of a housing having a pair of handles, which when squeezed, advance the screw away from the upper surface of the board to set the anchor in or below the board.
One such tool or gun is that which is disclosed in U.S. Pat. No. 4,932,638, issued Jun. 12, 1990. The tool disclosed therein is comprised of a housing having a rod slidably positioned therein. A slide element is attached to the forward end of the rod and has a slot that is adapted to loosely receive the head of the screw of an expansion bolt. A ratcheting mechanism is actuated by squeezing a pair of handles to move the rod away from the upper surface of the support structure to which the expansion bolt is to be attached.
Once the rod has moved sufficiently to set the anchor on the expansion bolt, the head of the screw is removed from the slide element and a trigger mechanism in the gun is pulled to release the rod. Springs in the housing return the rod and slide element to their original positions within the housing and the gun is now ready for setting another expansion bolt.
The prior art tool of the above-cited reference works well in most routine installations where the expansion bolt is readily accessible and where the screw of the expansion bolt has a head that easily engages the slot in the slide element of the tool. However, there are other installations that require the setting of a relatively large number of expansion bolts where these known, prior art guns can not be used; e.g. where (a) remote locations where the anchor portion of the expansion bolt is not readily accessible to the gun and (b) the screw of the expansion bolt is threaded along its entire length (i.e. has no head).
An example of such an installation is one that involves the mounting of solar energy arrays onto certain types of roofs (e.g. cement, ceramic, and like tiles such as “Spanish tile” roofs). In such installations, supports for the array must be mounted onto the tops of the arched or curved tiles, themselves. This presents a real problem since this type of tile is not a reliable support structure to which the necessary expansion bolts can be anchored. Due to the relatively fragile nature of such ceramic or cement tiles, the forces exerted by the anchors on the tiles can easily crack and seriously damage the tiles during the operational life of the array which is obviously unacceptable.
In installations of this type, it is neither practical nor economical to remove and then replace the affected tiles to install the necessary expansion bolts. Accordingly, to install such solar arrays efficiently in the field, an installer must be able to quickly and effectively set the required, relatively large number of expansion bolts without having to remove and replace tiles on the roof.
Recently, a novel technique has been developed for installing solar arrays onto these types of arched tile roofs which does not require the removal of any of the tiles. Basically, aligned holes are drilled through both a selected tile and the decking below on which the tile is mounted. The decking, e.g. plywood, may actually be up to 6 inches below the top of the arched surface of the arched tile. An expansion bolt is lowered through the aligned holes and the anchor on the expansion bolt is set below the lower surface of the decking. The screw of the expansion bolt extends upward through the hole in the tile and a support for the solar array is mounted thereon. For a more detailed description of such a technique, see co-pending and co-assigned U.S. Provisional Patent Application Ser. No. 60/463,359, filed Apr. 16, 2003, which is incorporated herein by reference in its entirety.
In such installations, the expandable portion of the anchor lies below the under surface of the decking while a flange on the anchor engages the top surface of the decking to keep the anchor from being pulled through the hole. The upper end of the screw of the expansion bolt is headless and extends upward through and above the drilled hole in the tile. In order to set the expansion bolt, the upper end of the headless screw must be gripped without damaging the threads on the screw. Further, the screw must then be pulled upward away from the tile without damaging the tile, itself. Still further the flange on the top of the anchor must be held in contact with the top of the decking as the screw is pulled upward in order to create the reactant forces necessary to set the anchor. It can readily be seen that none of the known prior art tools are capable of performing all of the necessary functions to set expansion bolts in such a remote environment.